METHOD FOR MAKING RECTANGULAR OPENINGS, CUTTER MANDREL, CUTTER Russian patent published in 2003 - IPC

FIELD: working materials by cutting, working through and dead openings. SUBSTANCE: method comprises steps of preliminarily working opening in zone restricted by its contour and subsequently finishing said opening. In order to increase accuracy of working, finishing operation is realized by fine planing. Working of rectangular opening is started by making holes in angular zones of contour of opening. Cantilever cutter mandrel includes boring bar with flange and cutting portion with cutter in cantilever portion of boring bar. In center of end of cutting portion there is groove for basing and fixing cutter in one of its two terminal positions. At one side of end of boring bar there is axle; at other side of said end there is eccentric member mounted with possibility of engaging by its eccentric portion with cutting portion. Boring bar is in the form of beam with given relation of geometry sizes. Cutter includes holder and head with cutting portion having one or two leading cutting edges and two side cutting edges at both sides relative to leading one. Holder is in the form of protrusion on lower surface of head. In order to realize such method, height of working portion of cutter head is determined according to given relation. EFFECT: improved accuracy of method due to enhanced design of cutter and cutter mandrel. 14 cl, 12 dwg